The EPICS-C fluorescence activated cell sorter/flow cytometer, located in the Biohazard Facility in the Chanin Building, is currently used for analysis of phenotypic markers on human leucocytes for correlation with clinical parameters; analysis of phenotypic cell surface markers on specific leucocyte subpopulations for determination of immunodeficiencies; staining of leucocyte subpopulations for the identification of human B- and T-lymphocytes involved in HIv target/infectivity studies; identification of fetal cell types as putative HIV targets; identification of HIv-infected subpopulations in fetal tissues and patient co-cultures; sorting of leucocyte subpopulations for studies directed at identification of fetal leucocytes in the maternal circulation, at isolation of HIV-infected fetal cells, at isolation of specific T-cell subpopulations for HIV-infectivity studies, at isolation of immunoglobulin-producing EBV-transformed AIDS B-cells, and at isolation of cells co-infected with HTLV-I and HIV, with acquisition of a profile flow cytometer, analysis of phenotypic cell surface markers, will be able to be carried out there, freeing significant time for those functions for which the EPICS-C is specifically designed, i.e. sorting, coordinated with two-color staining. Both the EPICS-C sorting and the profile analysis capability will be available to all CFAR investigators.